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141.
It is known that the localized surface plasmon resonance (LSPR) wavelength of plasmonics is highly dependent on compositions and geometry of plasmonics as well as the surrounding environments. Here, monodispersed Au@Ag core-shell nanoparticles (Au@Ag NPs) were prepared by carefully optimizing the shell thickness of Au@Ag NPs, and the presence of hydrogen sulfide (H2S) would significantly alter the LSPR wavelength. On the basis of this, a photothermal paper sensor for on-site recognition of H2S was constructed with a visual detection limit of 12.8 ng/L. 相似文献
142.
143.
Oxido‐peroxido W(VI)‐histidine–MgAl‐layered double hydroxide composite as an efficient catalyst in sulfide oxidation 下载免费PDF全文
Mohammad Nikkhoo Mojtaba Amini S. Morteza F. Farnia Arshad Bayrami Mojtaba Bagherzadeh Sanjeev Gautam Keun Hwa Chae 《应用有机金属化学》2018,32(6)
Oxido‐peroxido W(VI)‐histidine–MgAl‐layered double hydroxide composite was prepared by using MgAl‐layered double hydroxide as a host and oxido‐peroxido W(VI)‐histidine complex as a guest. The composite was characterized by XRD, IR, EDX,SEM and TEM techniques. This composite is tested for catalytic selective sulfoxidation reactions using hydrogen peroxide as oxidant showing good to moderate conversion along with high selectivity. 相似文献
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145.
Viqar Uddin Ahmad Sadia Bader Saima Arshad Amir Ahmed Afsar Khan Shazia Iqbal Munawwer Rasheed Rasool Bakhsh Tareen 《Magnetic resonance in chemistry : MRC》2010,48(4):304-308
Two new acylated flavonol glycosides, 3‐O‐{[2‐O‐β‐D ‐glucopyranosyl]‐3‐[O‐β‐D ‐glucopyranosyl]‐4‐[(6‐O‐p‐coumaroyl)‐O‐β‐D ‐glucopyranosyl]}‐α‐L ‐rhamnopyranosyl‐kaempferol 7‐O‐α‐L ‐rhamnopyranoside and 3‐O‐{2‐[(6‐O‐p‐coumaroyl)‐O‐β‐D ‐glucopyranosyl]‐3‐[O‐β‐D ‐glucopyranosyl]‐4‐[(6‐O‐p‐coumaroyl)‐O‐β‐D ‐glucopyranosyl]}‐α‐L ‐rhamnopyranosyl‐kaempferol 7‐O‐α‐L ‐rhamnopyranoside, trivially named as brauhenefloroside E (1) and F (2), respectively, were isolated from the fruits of Stocksia brauhica and their structures were elucidated using spectroscopic methods, including 2D NMR experiments. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
146.
Ajay Kumar Tausif Monif Arshad Khuroo Dinakar Sasmal Dipanjan Goswami Vijay Kumar Lahkar 《Biomedical chromatography : BMC》2011,25(6):680-688
LC‐ ESI‐ MS/MS simultaneous bioanalytical method was developed to determine acitretin and its metabolite isoacitretin in human plasma using acitretin‐d3 used as the internal standard for both analytes. The compounds were extracted using protein precipitation coupled with liquid–liquid extraction with flash freezing technique. Negative mass transitions (m/z) of acitretin, isoacitretin and acitretin‐d3 were detected in multiple reactions monitoring (MRM) mode at 325.4 → 266.3, 325.2 → 266.1 and 328.3 → 266.3, respectively, with a turbo ion spray interface. The chromatographic separation was achieved on an Ascentis‐RP amide column (4.6 × 150 mm, 5 µm) with mobile phase delivered in isocratic mode. The method was validated over a concentration range of 1.025–753.217 ng/mL for acitretin and 0.394–289.234 ng/mL for isoacitretin with a limit of quantification of 1.025 and 0.394 ng/mL. The intra‐day and inter‐day precisions were below 8.1% for acitretin and below 13.8% for isoacitretin, while accuracy was within ±7.0 and ±10.6% respectively. For the first time, the best possible conditions for plasma stability of acitretin and isoacitretin are presented and discussed with application to clinical samples. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
147.
Acid-mediated cyclizations of SEM-protected heterocyclic anilines and adjacent hydroxyls or enol ethers during SEM deprotection are reported. Strategies to suppress these side reactions and their potential synthetic utilities are also described. 相似文献
148.
Sanjay Gurule Dipanjan Goswami Arshad H. Khuroo Tausif Monif 《Biomedical chromatography : BMC》2010,24(5):497-505
A newly developed LC—APCI mass spectrometric method is described for human plasma determination of atovaquone using lapachol internal standard. A single‐step protein precipitation technique for plasma extraction of atovaquone achieving mean recovery of 94.17% (CV 8%) without compromising sensitivity (limit of quantitation 50.3 ng/mL) or linearity (50.3 ng/mL—23924.6 ng/mL) is delineated in this paper. Heated nebulizer in negative multiple reaction monitoring mode was employed with transitions m/z 365.2 → m/z 337.1 and m/z 240.9 → m/z 185.7 for atovaquone and lapachol respectively in this liquid chromatographic–tandem mass spectrometric method. Excellent chromatographic separation on a Synergi 4 μ Polar‐RP 80A (150 × 2.0 mm) column, using 100 μL of plasma extraction volume along with 10 μL of injection load, completing analysis run‐time within 2.5 min, highlights this simple yet unique bioanalytical method. The developed method can be successfully applied to pharmacokinetic studies on atovaquone suspension administered in healthy volunteers or HIV‐infected patients. Moreover full method validation results not published before are presented and discussed in detail for the first time in this article. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
149.
Khuroo AH Gurule SJ Monif T Goswami D Saha A Singh SK 《Biomedical chromatography : BMC》2012,26(5):636-649
A bioanalytical method was developed and validated to estimate donepezil, 6‐desmethyl donepezil and 5‐desmethyl donepezil simultaneously in human plasma using galantamine as an internal standard (IS). The chromatographic separation was achieved on a reverse‐phase XTerra RP (150 × 4.6 mm, 5 µm) column without affecting recovery (mean recovery > 60% with CV < 10%) for all analytes. ESI‐MS/MS multiple reaction monitoring in positive polarity was used to detect mass pairs for donepezil (m/z 380.3 → 91.3), 6‐desmethyl donepezil (m/z 366.4 → 91.3), 5‐desmethyl donepezil (m/z 366.4 → 91.3) and galantamine m/z (288.1 → 213.0). The linearity was established over a dynamic range of 0.339–51.870, 0.100–15.380 and 0.103–15.763 ng/mL for donepezil, 6‐desmethyl donepezil and 5‐desmethyl donepezil, respectively. The current method shows that minimal conversion of labile metabolites to parent donepezil in plasma as stability was successfully achieved for 211 days at ?15 °C storage temperature. The method was successfully applied to a clinical study after administration of 10 mg donepezil tablets to healthy male Indian volunteers. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
150.
M. Arshad K. Masud M. Arif S. Rehman M. Arif J. H. Zaidi Z. H. Chohan A. Saeed A. H. Qureshi 《Journal of Thermal Analysis and Calorimetry》2009,96(3):873-881
The thermal behavior of poly(methyl methacrylate) (PMMA) was studied in the presence of AlBr3 using TG-DTA-DTG, IR and Py-GC-MS techniques. Degradation products were identified. It was found that PMMA started degrading
at a lower temperature due to the generation of free radicals (Br•), being the product of decomposition of AlBr3. Despite early destabilization of the system, stabilization zone was also highlighted. Flammability test was conducted to
check the affectivity of AlBr3. Degradation mechanism has been proposed. Pyrolysis of the system (PMMA–AlBr3) was also monitored by heating it at different temperatures. 相似文献